1. Field of the Invention
The present invention relates to a projecting device, more particularly to a color wheel used in a projecting device.
2. Description of the Related Art
The prior art of balancing a color wheel mainly includes the following two methods; the first method is to apply adhesive materials onto the motor or the carrier, but such method may easily cause interference to the mechanism or optical path; the second method is to drill holes on the carrier in order to balance the color wheel, but such method has difficulties to control the exertion of force, and thus may easily cause damages to the bearing, and the metal powder or bits may easily contaminate and scrape the coating surface and thus causes defects.
To solve the shortcomings of the prior art methods, the present inventor discloses a color wheel that forms a annular groove at the position originally intended for the drilling holes on the external surface of the carrier, so that when the color wheel cannot balance its rotation, a balancing material, such as glue, is filled into the annular groove instead of drilling holes to attain the effect of balancing the color wheel. In the meantime, it can avoid excessive filling of materials that goes beyond the height of the external surface of the carrier and then generating the interference.
The objective of the present invention is to provide a color wheel with balancing groove, wherein a balancing material is filled into the annular groove disposed on the external surface of the carrier to avoid excessive filling of materials and resulting the interference.
In order to attain this objective, the color wheel of the present invention comprises a carrier, substantially in the shape of a circular disc, having a central axis, a external surface, and a periphery, which rotates along the central axis; a set of filter plate, having at least a filter plate. The set of filter plate shares the same central axis of the carrier, wherein a circular groove is disposed on the external surface of the carrier, and stays away from the periphery at a predetermined radial distance, and a balancing material can be added into the circular groove to attain the purpose of balancing the color wheel.